International Journal of Engineering and Techniques -Volume 4, Issue 5, Sept - Oct 2018

Transcription

1 RESEARCH ARTICLE OPEN ACCESS Bus Body Analysis for Dynamic and Static load Abdul Malik 1, Prashanth A.S 2 1(PG Student, Department of Machine Design, Dr Ambedkar Institute of Technology, Bangalore) 2 (Assistant Professor, Department of Mechanical Engineering, Dr Ambedkar Institute of Technology, Bangalore) Abstract: Transports are the preeminent method of road transportation. The look of the vehicle body depends chiefly driving the execution requirement underneath varying sorts of stacking and managing conditions separated from those of the street conditions. The model investigation moreover, static basic associate analysis of an enunciated urban transport body, completed with the FEM. A bus body in while operating in loading conditions is exposed to various loading conditions which leads to stresses, vibration, noise in many parts of the bus structure. The structure requires necessary strength, stiffness and fatigue characters to withstand these loads. The purpose of this work is to analyse the response of the structure during static and dynamic loading conditions. In order to analyse, the tool called ANSYS is used. Keywords Static load, Dynamic load, bus body structure, ANSYS 14.5, FEM. I. INTRODUCTION Automotive chassis is a skeletal frame on which distinctive mechanical parts like motor, tires, rotate assemblies, brakes, coordinating and so forth are shot. The chassis is believed to be the most basic component of an automobile. It is the most noteworthy element that gives quality and security to the vehicle under different conditions. Nature of transport chassis relies on upon the limit of transport. It can be tailor-made according to the requirements and can be profited with elements like transverse mounted motor, air suspension and also hostile to move bars. An all around manufactured transport chassis offers different advantages like high torque from low revs, superior brake performance and more. Transport chassis designed for urban courses contrasts from the one manufactured for rural courses. For transport frameless, chassis development is utilized. In this frame less chassis sort every one of the components is appended to the body. Every one of the elements of the frame done by the body itself. Because of elimination of long frame it is less expensive and because of less weight most economical too. Just disservice is troublesome in repairing. The design of the inner transport skeleton structure is the premise of different transport developments in the transport enterprises. It contains the structure of tubes with various cross territories are planned inside decided shapes in light of the outline thinking. The vehicle body can be isolated into three areas; the undercarriage and engine, structural body, inside and outside parts. The contains transport body have six primary parts the left and right casing side, the front and back casing side, the top and base edge side. In that the top casing side is at some point called housetop outline side. The base edge side is moreover called floor outline side. The right and left side are comparable however the left side is ordinarily made out of two voyager entryways. At that point again, the right side has two entryways the driver entryway and crisis entryway. In like manner, the both edge sides are displayed by mirrors and welded with sheet metal. They are concerned to be key parts. They should be strong. The parts should be explanatory tests by in any event reproduction or physical test. Torsion and reshaping tests are generally mimicked by FE ISSN: Page 123

2 analysis. Regardless, the nature of this outline is influenced by the assembling. II. METHODOLOGY The methods and methodology in order to carry out the bus body analysis and modelling of the same involves the below methods or the procedure. 1. Geometric Modelling: The 3D figures are created using CATIA. 2. Finite Element Analysis: The 3D figures l created using CATIA is transferred to FEM software ANSYS14.5 and is meshed and that model is called as Finite elemental model. III. FINITE ELEMENT APPROACH The FEM is a capable instrument for the numerical structure to get react in due request with respect to a huge segment of the issues experienced in building examination. From static, warm and warm trade, fluid stream, depletion related issues, electric and enchanting fields. The bits of knowledge of finite element method can be used to these organizing issues. In this method, the zone over which the examination is considered is secluded into different finite elements. Adding cut-off canters are utilized to decrease the direct at an infinite field of canters to finite number of focus interests. These obsessions outline the finite elements. The elements are interconnected by focus canter interests. Every one of the elements is gathered and the basics of headway and concordance are to be fulfilled between neighbouring elements. An astounding blueprint can be picked up to the general methodology of direct logarithmic conditions, gave the motivation behind restraint states of the true blue structure are fulfilled. Plan of these conditions gives us the gathered direct of the continuum. To be getting a correct procedure in the scope of quickly fluctuating parts, more number of humbler elements must be utilized. Fig 1 Flow chart 3. Suitable Boundary Conditions: The meshed model is then applied with certain boundary conditions and steps of analysis are done using Ansys. III A) STEPS INVOLVED IN FEM 1. Modelling ISSN: Page 124

3 2. Description of continuum 3. Selection of proper interpolation model 4. Derivation of elemental stiffness matrix 5. Assemblage of elemental stiffness matrix 6. Enforcing the boundary condition 7. Solution of system equation to find the nodal displacement 8. Computation of element strains and stresses IV. ANALYTICAL STUDY 2. Material properties:- 1. Modal analysis:- An analysis of measured information is a procedure in which the measured recurrence response functions are broke down in order to locate a theoretical model that most nearly resembles the dynamic behaviour of the structure under test. This piece of the modal test is called experimental modal analysis, in spite of the fact that this term is frequently incorrectly utilized for the whole modal test. The procedure of information analysis continues in two phases. 1. Recognizing the proper sort of model (with thick or structural damping). This choice is frequently by and by limited by programming utilized for the modal analysis. Most of software bundles work with one kind of damping and give no decision to the client. 2. Determining fitting parameters of the picked model. This stage, additionally called modal parameters extraction, is finished by bend fitting of the measured recurrence reaction capacities to the theoretical expressions. Density ton/m 3 Young's modulus - 2E+11 pa Poisson's ratio Bulk modulus E+11 pa Shear modulus E+11 pa Coefficient of thermal expansion - 1.2E c^-1 Reference temperature c 3. Geometrical specification in bus body Length 11.66m Width 2.47m Height 3.24m Wheel base 2.16 ISSN: Page 125

4 4. Material composition Composition % Carbon Manganese Phosphorus Sulfur Silicon, max 0..4 Chromium, max 0.08 Copper, min 0..2 Molybdenum Nickel Vanadium. max V. GEOMETRIC MODELLING FEM MODEL:- Fig 3 meshed model ANSYS Meshing is a general-purpose, intelligent, automated high-performance product. It produces the most appropriate mesh for accurate, efficient solutions. A mesh well suited for a specific analysis can be generated with a single mouse click for all parts in a model. Applying boundary condition:- This step involves the application of boundary conditions. Here the bottom of the bus is fixed for carrying out the process of modal analysis. They are applied to fix the displacement or load on a specific model. Also application of boundary condition on fem model avoids singularities in the model. Fig 2 Bus body model A bus body has been made using CATIA V5. Meshing:- Fig 4 boundary conditions applied ISSN: Page 126

5 VI. RESULTS AND DISCUSSIONS Static analysis:- Static analysis helps in finding out the effects of study loading conditions on a bus body. These are done by ignoring the inertia and damping effects. Max. Total deformation:- The maximum total deformation using Ansys was carried out and shown in figure below. Maximum principal stresses:- The maximum principal stresses found out using ANSYS is shown in figure below. Fig 7 maximum total deformation DYNAMIC ANALYSIS:- Fig 5.maximum principal stresses Minimum principal stresses:- The minimum principal stresses found on the bus body was carried out using Ansys and is shown below. The bus body structure was analysed for static conditions in the previous case. The results we got are for steady conditions. The buses in their normal operating conditions are subjected to various types of time dependent loading (dynamic) conditions (such as acceleration, braking and speed breaker etc). Fig 6 Minimum principal stress Fig 8 Dynamic analysis ISSN: Page 127

6 VII. CONCLUSION International Journal of Engineering and Techniques -Volume 4, Issue 5, Sept - Oct 2018 The free model analysis and static structural analysis of a verbalized urban transport body, with an aggregate length of m, has been performed through Global Finite Elements Method. The structure behaviour towards four distinctive loading conditions, illustrative of its run of the mill duty cycle, has been broke down: the activity of gravitational acceleration, the braking at the upper deceleration limit of the vehicle,2g load and impact load condition to acquired stress, strain and displacement. Sensitivity investigations in order to assess the transport body performances have been done in order to get dependable outcomes in terms of stiffness and displacements of the transport body. 1. Linear static structural analysis has been carried out to estimate the maximum stress, strain and deformation in bus body. It is found that peak stress of Mpa, total deformation of mm is obtained along the hook 2. Find the initial modes and corresponding natural frequency in bus body. 3. Fatigue analysis of bus body was carried out for cycles of start-up and shutdown, the fatigue life results obtained is more than cycles, hence the design is safe. 4. Weight of in bus body which is Optimization of bus body to increase the life and efficiency. References [1].Chandna P., Bhushan G., Singh V. P., Kumar D. and Kumar A., Finite element analysis of a bus body structure using CAE tools. Kurukshetra University, 2008 [2].S Manokruang, Methodology of Bus-Body Structural Redesign for Lightweight Productivity Improvement, AIJSTPME, 2009, 2(2), [3].Abaqus Documentation v [4].P Eriksson, Optimization of a Bus Body Structure, Heavy Vehicle Systems, A Series of the Int. J. of Vehicle Design, 2001, 8(1),1-16. [5].Lan F, Chen J and Lin J. Comparative analysis for bus side structures and lightweight optimization, Proc. Instn Mech. Engrs, 2004, [6].Yi L. Bus skeleton lightweight design based on reduced model and mixed variables optimization. in Computer Science and Information Technology (ICCSIT), 2010.A New Design and Analysis of BUS Body Structurewww.iosrjournals.org47 Page [7].X Zhang. A Study on Shape Optimization of Bus Body Structure Based on Stiffness Sensitivity Analysis. Computer- Aided Industrial Design & Conceptual Design, [8].A Gauchía, Torsion Stiffness and Weight Optimization of a Real Bus Structure, International Journal of Automotive Technology,2010, 11(1), [9].Genta G. The Automotive Chassis: Components Design, Springer, 2009 [10].Reimpell J. The Automotive Chassis: Engineering Principles, Butterworth Heinemann, ISSN: Page 128